Reddit reviews Urban Shelf (Black

This app is great. For those concerned with keeping this on your bed, next to your head, or if you're concerned about knocking it off, here's a fix.

I slide a thin board between my mattress and box spring, and use that as a shelf for my phone, while the Sleep alarm is tracking. It works great, and I see detailed graphs and data from each night. Also worth noting that I don't see any interference from my partner sleeping in the same bed.

I started with a board, but that was too thin and broke. Then I found this thing at the container store, which works pretty well.
https://www.amazon.com/gp/aw/d/B005JPAY9I

I still think I prefer just a simple board though, since it was lower and had less chance to get in my way as I was exiting bed.

I'm not sure how much you're going for style vs function, but I've seen tables around that hook or insert to the side of your bed that would work for you. Like this one.

Otherwise, a small table to the side of the bed would work. I have a full night stand on one side of my bed, and a nicer version of this metal/would table on the other.